Air compressor



July 23, 1946. w J ROULEAU 2,404,660

AIR COMPRESSOR Filed Aug. 26, 1945 2 Sheets-Sheet 1 Elm/23, 19%. w. J. ROULEAU 2,404,560

AIR COMPRESSOR Filed Aug. 26, 1945 2 Sheets-Sheet? \NvENToR WW 09M Patented July 23, 1946 UNITED STATES PATENT Y OFFICE Am COMPRESSOR Wilfred J. Rouleau, Quincy, Mass. Application August 26,- 1943, Serial No. 500,028

This invention relates to compressors for compressing air and other gas, and especially to that type of compressor that is constructed to deliver atomized liquid to the cylinder for the purpose of absorbing the heat of compression.

In the operation of an air compressor having a reciprocating piston, the compression of the air in the cylinder occurs during the first part of the compression stroke, and before the piston hastraveled through its entire stroke, the maximum pressure has. been reached and the exhaust valve opens to permit the discharge of the compressed air from the cylinder, such discharge occurring during the last portion of the compression stroke.

The heat of compression is developed while the pressure in the cylinder is increasing, and no additional heat of compression is developed after the maximum pressure has been reached and while the compressed air is being delivered from the cylinder.

It is one of the objects of my presentinvention to provide an air compressor in which the atomizedliquid is delivered to the cylinder during that portion only of the compression stroke inwhich heat of compression is being generated, that is, during that portion only of the compression stroke in which the pressu re increasing, and in which the delivery of atomized liquid to the cylinder will be cut 'off or terminated as soon as the maximum pressure hasbeen reached and. will remain cut off during the time that the piston is completing its stroke and is forcing the compressed air out' of the cylinder. Ifatomized liquid is delivered to the cylinder in suflicien't quantity to absorb the'heat of compression as it is developed. any additional atomizedliouid thatis delivered to the cylinder after development of the heat of compression ceases and during the time when the compressed air is being forced from the cylinder willbe wasted.

With my invention the delivery of the atomized liquid to the cylinder of thecompressor is so controlledthat it isdelivered while the heat of compression. is being developed, and its delivery ceases as soon as the maximum pressure in the cylinder has been reached.

In orderto give an understanding of my in- Vention, I have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claims.

In thedrawings: Fig. 1 is a view, partly in elevation and partly '4 Claims. 01. 230-203) in section, of a compressor embodying my invention.

Figs. 2 and 3 are diagrammatic views illustrating the operation of the compressor. In the drawings I indicates generally a compressor for compressing air or other gases embodying my invention, said compressor having the usual cylinder'2 in which operates a reciproeating piston 3. The piston is shown as con nected by a piston rod 4 and connecting rod 5 to a crank 6 on the power-driven shaft 1, the latter being equipped with the usual fly wheel t?v The cylinder 2 herein shown is a double acting cylinder, it having two inlet ports l5, l6 controlled by inlet valves l1 and I8, which open into an inlet manifold l9 having an intake pipe 20 leading thereto. The cylinder is also provided with the two outlet ports 9, ll! which are controlled by outletvalves H, l2 respectively, said communicates with a delivery pipe I4.

The parts thus far describ'edare such as are commonly found in air compressors and form no part of my present invention.

" Situated in the cylinder head 2| is an atomizeri'22 'adapted to deliver atomized liquid into the cylinder 2, said atomizer being supplied with liquid through a supply pipe 2'3, The other cylinderhead 24 is alsoequipped with an atom-- izer 25 which is adapted to deliver atomized liquid'into the cylinder on the left hand side of the piston 3, said atomizer 25 being supplied with liquid through the supply pipe 26. In the operation of an air compressor of this type, the air or gas in the cylinder will besubjected to -an increase in pressure as the piston moves from one end to the other of its stroke, and when the piston has traveled through part of its stroke in either direction, the maximum pressure 410) to which the air is to becompressed has been reached, and when this maximum pressure has been reached, the outlet valve II or l2 will open and the air at this maximum pressure will be forced out of the cylinder-intothe outlet manigin fold I3 and will thus be delivered through the delivery pipe I4. v 0

As stated" above the compressing of the gas develops heat of compression but the develop ment of such heat of compression ceases whenthe maximum pressure has been reached, and during the latter part, of the stroke in either direction when the compressed air is being delivered from thecylinder, there will be no development of heat of compression. 1 In'accordance with mypresentinvention, I

valves opening into an outlet manifold 13 which have provided means whereby atomized liquid will be delivered from the atomizer 22 during that portion only of the compression stroke toward the right in which the heat of compression is being developed, the delivery of atomized liquid from said atomizer 22 ceasing as soon as the maximum pressure in the cylinder has been reached. Similarly, during the compression stroke toward the left, the atomizer Z willbe operative to deliver atomized liquid into the cyline der during that portion only of the compression stroke in which the pressure of the air is increasing and heat of compression is being developed, such delivery of atomized liquid from the atom; izer 25 ceasing as soon as the maximum pressure has been reached and the valve l2 opens to permit discharge of the compressed air from the" cylinder.

Various ways of controlling the delivery of atomized liquid from the atomizers 22, 25 so that they will function. as above. set; forth may be employed without departing from my invention. I have, however, shown in the. drawings a simple construction adapted for this; purpose and which comprises a pump cylinder 21' having: a. pT-lmp pi ton 28' operating therein. This. pump cylinder is a double=acting cylinder and is. provided with two. inlet ports 29., 3,0. controlled by the u u l spring=pressed inlet valves. 31, 32. These. inlet ports 29, 3 0. communicate with an inlet manifold 33. which is supplied with liquid through a S1111-- ply pipe 34. The pump. is also provided with two outlet ports 3.5, 36. controlled by outlet. valves. 3.1, 3-8. The outlet valve 3.5 opens into. a chamber 339 with which the supply pipe 2:3 communicates, and

the outlet valve 38: opens into a chamber All with.

which the supply pipe 2.8 communicates. This. pump piston 28 is. operatively connected to the shaft l of the compressor so that. the pump. op-

erates synchronously with the compressor. When the pump. piston 28 moves to the. right from the position shown in Fig. 1, the water or other liquid will be forced through the outlet valve 35 and pipe. 23 to the atomizer 22 and thelatter will thus. be operative to deliver atomized liquid to the right hand end of the compression cylinderl 1 On the other hand when the pump piston 28. moves toward the left, it will operate to. force liquid through the outlet valve 38, chamber 40. and pipe 2-6 tothe; atomizer 25 thus causing thelatter to deliver atomized liquid to the left hand end of the compressor cylinder 2-.

The relation between the pump. piston 28 and the compressor piston 3 is such that during that portion only of the compression stroke of'the pi's.-. ton 3 toward the right in which the air is being compressed the pump piston 28 will'be moving to the right and thus forcing atomized liquid into the; right hand' end of the compressor cylinder. By the timetha-t the maximum pressure in the cylinder 2- has been reached and the valve H is ready to open, the pump piston 28 has reached the end or its stroketo the right with, the result that further delivery of atomized liquid from the atomizer 22 will cease and no atomized liquid will be delivered during the remainder of: the stroke to the right of the compressor piston 3 and while the compressed airisbeing delivered through the let r $imilarlvduringthe first part of the movement ofthe compressor piston 3 to the left in Fig. l, the pump piston 28 will be moving to the left and thus forcing water through the atomizer 2 5 with the result that atomized liquid will be 4 delivered to the left hand end of the cylinder 2. By the time, however, that the maximum pressure has been developed in the compressor cylinder 2 on the left hand side of the piston, the pump piston will have reached the end of its stroke to the left and delivery of atomized liquid from the atomizer will, therefore, cease, and no atomized liquid will be delivered from said atomizer during the remainder of the stroke of the piston 3 to the left and while the compressed air is being delivered through the discharge port Ill, The pump piston 28 is provided with the usual piston rod 4! which is connected by a connecting rod 42 with a crank 43 on a shaft 44. This shaft 44 and also the shaft 1 are provided sprocket wheels 45, 46 of the same diameter that are connected by the sprocket chain 41 i so that the crank 6 of the compressor and the crank 43 of the pump are rotating synchronously. The crank 43 of the pump, however, is loated somewhat advance. of 5.01? th ompressor as shown in th 'dia ra ati vi ws 2, and he. arran em nt beingsu h th the cra i oi'the pump arrive at a. dead center position som wha ad ance of the crank 6 he mpre s F 2 and a so inFis 1, the cran 4 of; pump has j t passed its dead cent r p sit. to the. left. the pu p ston h just: b n i smovementtoward: e r ht. At this ime he ompress r piston 3; is i l r v l n toward the. left, and the maximum p e s e at the l ft hand end; o thc c l nderhas n reach d a the compresse air isbeine delivered through the outlet valve l2. Air is also being admitted to the right hand end O the com- Pre ser yl nd r th o h the in et: port: I5: The continued movement of the pump piston to the ght w ll fi rc iqui hrouehthe atomizer 1 a atom z d: qu d wil b d livered to the right hand. end of h ompressor cylinder dun ing the latter part of the suction stroke, and; this live y of a o i d: iq id: will ont nue during the: final p t of th m vem ntof: the compress r p ston 3 to the left and. while: sa d p ston moves to the right to compress the. air, in the righ ha d end of the cylinder. howev r; byh time the maximum pressure has been developed t e. ri h nd end of the cylin r the p p I to. the right.

left. hand end of the compressorcylinder during the final. portion of the, compressor piston Stroke Said.. atomi er 5- Will continue active, during th t p r ion or the.- movement of the compr ssor piston 3 to. the left. in. w i hlthe, a r is. bein compressed, butby the tim the piston 3 reaches the position shown in, 1 and 2 in which the maximum pressure has been developed at the left of the piston and the compressed air is being dischargedthrough the outlet port l-0 the pump piston 28 will have reached the end of its stroke to the left and will have begun its movement to the right, therebyrendering.- the atomizer 2.5 inoperative and: the atomizer 22 operative.

It will, therefore, be seen that with my device each atomizer is operative to deliver atomized liquid to the cylinder during that portion only of the compression stroke in which the heat of compression is being developed, each atomizer becoming inoperative when the maximum pressure has been reached and the compressed air is being delivered from the compressor cylinder.

While I have illustrated one mechanism adapted to accomplish this end, yet I do not wish to be limited to the construction shown as other mechanical devices might be employed for so moving the pump piston relative to the compressor piston as to insure the delivery of the atomized liquid during the portion only of the compression stroke in which heat of compression is being developed.

I claim:

1. An air compressor comprising a cylinder, a reciprocating piston operating therein, an atomizer for delivering atomized liquid into the cylinder, a reciprocating pump for forcing liquid through said atomizer, and means to operate said pump in timed relation with the compressor but out of step therewith and in such relation thereto that the compression stroke of the pump terminates considerably prior to that of the compressor, whereby said pump will become inoperative to deliver atomized liquid into the compression cylinder during the latter part of the compression stroke of the compressor piston in which the compressed gas is being delivered from said compressed cylinder.

2. An air compressor comprising a cylinder having inlet and outlet ports, a piston in said cylinder, means to deliver atomized liquid to the compressor cylinder during the first part of the compression stroke of said piston, and means pump having a reciprocating piston, a crank shaft for operating said pump piston, means connecting the two crank shafts so that they rotate at the same speed but out of step with each other with the crank of the pump crank shaft considerably in advance of that of the compressor crank shaft, whereby the pump piston will reach the end of its pressure stroke and will hence cease to force liquid through the atomizer during the latter portion of the compression stroke of the compressor and while the compressed gas is being discharged from the compressed cylinder.

4. An air compressor comprising a cylinder having inlet and outlet ports, a piston in said cylinder, means to deliver atomized liquid to the compressor cylinder during the final portion of the inlet stroke and the first part of the compression stroke of said piston, and means operating automatically to render said first-named means inoperative during the final portion of said compression stroke, whereby the delivery of atomized liquid to the compressor cylinder will cease during the time that the compressed gas is being delivered from said cylinder.

WILFRED J. ROULEAU. 

